One thing about the RPV/Quadcopter debate that is rarely mentioned is the reason why they don't use ADS-B transponders. The FAA requires ADS-B trasponders to have high accuracy GPS, and that pushes the cost to over $2,000 per device. It would be logical for the FAA to relax the GPS requirement slightly, so a cheap GPS module is sufficient to alert nearby aircraft of RPV activity over a certain altitude (eg. 200ft AGL…
Model aircraft have existed for a long time and there's been a good relationship with the FAA and few incidents. The challenge is that technology has advanced to the point that these modern "drones" are almost too easy to fly. Any idiot can watch some YouTube videos and then they think they're a pilot. Given that, to the extent possible the aviation regulations should be enforced at the device level to make these things as idiot proof in terms of busting airspace regs as they are idiot proof to fly.